Hello,
Even if there was no ejaculation inside, yet sometimes there are active sperms in the prostatic secretions or precum which can cause pregnancy. But it depends on the timing of the intercourse. Pregnancy occurs only during the time of ovulation. Ovulation is the release of a single, mature egg from a follicle that developed in the ovary. It usually occurs regularly, around day 14 of a 28-day menstrual cycle.
I hope it helps. Take care and regards.
This irregular period had a couple of blood clots, one was small the other was a decent size, and one night nothing was on the pad but when I went to use the bathroom, I urinated blood.